The manufacturing of pneumatic tires for motor vehicles of nearly all sizes entails the steps of creating the carcass and attaching thereto the tread and sidewalls, which are made of uncured rubber. The combination of carcass, tread and sidewalls, prior to curing of the rubber, is called a ‘green tire.’ The final step in the manufacture of a tire is the insertion of the green tire into a tire mold, wherein the tire is heated to a sufficiently high temperature to vulcanize the tire. The tire is then removed from the mold and the manufacturing process is complete.
Whereas the manufacturing of tires for automobiles is a straightforward process involving relatively light-weight green tires, the manufacture of large tires for industrial or large off-road type vehicles of the sort used in earth moving and construction work entails the handling of very large green tires weighing hundreds of pounds. Because the tread of these large tires are very thick and massive, it requires a lot of heat transfer to the tread area of the tire in order to properly cure the tread. The sidewalls of the tire are much thinner and thus require less heat as compared to the thick tread. One problem that may arise is that the sidewall of the tire is cured the desired amount, while the tread is under cured. Alternatively, the tread may be cured the desired amount, while the sidewall and belt edges may be overcured. Thus it is desired to have an improved tire mold which allows for the correct temperature of the tread and sidewall zone of a tire mold.